Findings reveal world's major river systems remain under pressure

Updated
November 26, 2012 13:40:00

New research into four of the world's major river systems, including the Murray-Darling has found that too much water is being taken out of them and the problems that's causing are expected to increase with climate change. The findings published in the journal Nature Climate Change reveal that environmental flows are not being met in the Colorado and Orange-Senqu Rivers and the Murray-Darling and Yellow Rivers remain under pressure despite government's attempting to intervene.

ELEANOR HALL: New research into four of the world's major river systems, including the Murray-Darling, has found that too much water is being taken out of them and the situation is only going to get worse with climate change.

The findings are published in the journal Nature Climate Change. They reveal that environmental flows are not being met in the Colorado and Orange-Senqu Rivers and that the Murray-Darling and Yellow Rivers remain under pressure despite government intervention.

Michael Vincent reports.

MICHAEL VINCENT: These four major continent crossing tributaries were chosen for a reason - they suffer long droughts or extensive floods.

JAMIE PITTOCK: We studied these rivers because, you know, this is really where the rubber hits the road of can you manage a river well when you can't depend on the river flowing consistently the same way from year to year.

MICHAEL VINCENT: Dr Jamie Pittock is a researcher at the ANU, he's also the director of international programs for the UNESCO chair in water economics and transboundary water governance.

And it's failures in governance of water extraction that's the major problem.

JAMIE PITTOCK: Governments have allowed people to take too much water out of the rivers and these societies, these governments have locked themselves into systems that they're fighting hard to change.

So for example in the United States there's actually a compact or an agreement between the states over the allocation of the rivers which the states refused to renegotiate even though it is essential to restore the health of that river system.

MICHAEL VINCENT: The researchers found climate change is expected to create even more problems.

JAMIE PITTOCK: Well for most of the rivers we looked at, it seems possible that they will get drier with climate change, but that's not a universal conclusion. It is possible that some of the rivers might get a little wetter but the magnitude of the climate change impact that has been modelled is much less than the volume of water that's being diverted by people at the moment.

MICHAEL VINCENT: The Federal Government's new Murray-Darling Basin plan has only just been finalised, but Dr Pittock says South Africa had good policy for its Orange-Senqu River system that failed because water continued to be taken out.

He says too many rivers no longer flow from source to sea.

JAMIE PITTOCK: Well yes sadly that's true, an increasing number of rivers around the world are described as closed, meaning that they don't reach the sea. A river that doesn't reach the sea is an indicator of poor management and what we're saying is that there's a whole lots of social and economic benefits that those rivers provide when they do reach the sea that these countries are losing out on and that we need to ensure that there's a basic level of river health to provide those services, whether it's drinking water or fisheries or floodplain forests or pastures for livestock, rivers need to reach the sea.

ELEANOR HALL: That's Australian National University researcher Dr Jamie Pittock ending that report by Michael Vincent.